Yellow-bellied Glider (south-eastern)  |  

Habitat critical to the survival of the yellow bellied glider (south eastern) may be broadly defined as areas containing the following attributes (noting that geographic areas containing habitat critical to survival needs to be defined by forest type on a regional basis) large contiguous areas of floristically diverse eucalypt forest; which are dominated by winter flowering and smooth barked eucalypts; including mature living hollow bearing trees and sap trees (see Appendix A) areas identified as refuges under future climate change scenarios short or long term post fire refuges (i.e.; unburnt habitat within or adjacent to recently burnt landscapes) that allow the species to persist; recover and recolonise burnt areas habitat corridors required to facilitate dispersal of the subspecies between fragmented habitat patches and or that enable recolonization or movement away from threats. yellow bellied gliders (south eastern) have a glide ratio (horizontal distance height dropped) of around 2.0; and corridors spanning gaps larger than the distance gliders are likely to be able to travel should be considered critical to the survival.
Extensive severe bushfires Status current Projections of higher temperatures and reduced mean Confidence rainfall for eastern Australia due to climate change are known leading to increased frequency and severity of bushfires (CSIRO Bureau of Meteorology 2015).
Climate change Increased temperatures Status Projections of higher temperatures and reduced mean and changes to current future rainfall for eastern Australia due to climate change are precipitation patterns Confidence leading to increased frequency and severity of droughts known and bushfires (CSIRO Bureau of Meteorology 2015).
Gradual declines in subpopulations of the subspecies in north eastern NSW may have occurred due to climate change; though this requires further investigation (Kavanagh et al. 2021).
The driving factors behind these potential declines are unclear; though climate change may be responsible through reductions to rainfall and increases in mean daytime and night time temperatures (R Kavanagh 2021. pers comm 10 August).
Rising temperatures will result in elevated water requirements for arboreal marsupials and in some cases water stress; forcing range contraction into climate refugia (Kearney et al. 2010 Krockenberger et al. 2012).
Indeed; climate change is likely to influence the distribution of the yellow bellied glider (south eastern) through a shift of bioclimates that support the subspecies habitat (Handayani et al. 2019).
A study modelling yellow bellied glider (south eastern) habitat loss due to climate change in south east Qld found that there will likely be substantial decreases in core and marginal habitat for the subspecies; even under low warming scenarios.
Climate change Protect all habitat projected to be suitable as refuge sites under future climate change scenarios (as informed by research) and maintain and establish connectivity to facilitate movement where possible.
Trend contracting The severity; frequency and scale of catastrophic bushfires will likely increase due to climate change.
It may also be declining due to threats associated with climate change (R Kavanagh 2021. pers comm 10 August).
Direct mortality due to fire occurs through lethal heating or sublethal inhalation of smoke; and indirect mortality occurs due to the loss of important habitat features and resources such as sap trees and live hollow bearing trees (Lunney 1987 Goldingay Kavanagh 1991 Bradstock et al. 2005).
Eyre (2005) found that the abundance of dead hollow bearing trees was significantly impacted by fire severity; and Goldingay (2021) found a negative relationship between dead tree abundance and occupancy.
Changes to the existing fire regime include a shift to very large fires occurring at shorter intervals; which is a threat to forest dwelling mammals in south and south eastern Australia (Lindenmayer 2015).
Though yellow bellied glider (south eastern) subpopulations may remain stable under natural fire regimes; an increase in the severity; size and frequency of fires is likely to have a large impact on the viability of many subpopulations.
However; such fire regimes will also cause a shorter term decline in the abundance of arboreal mammals due to direct impacts (McLean 2012).
Interactions of timber harvesting with fire Timber harvesting can interact with fire to compound the impact of bushfires on hollow bearing trees.
Hollow bearing trees are also threatened by post fire salvage timber harvesting (Noss Lindenmayer 2006 Lindenmayer et al. 2008).
Monitor the incidence and impacts of bushfire and timber harvesting in the subspecies range; particularly in areas adjacent to those burnt in the 2019 20 bushfires.
This should include modelling of the health of significant habitat species; eco physiological controls on sap flow; and future distribution of high fire risk and extreme events (especially drought and bushfires).
Past decline due to habitat loss; fragmentation; forestry and altered fire regimes Prior to the 2019 20 bushfires; trends of population decline; and the rate of this decline; could not be reliably estimated.
Future decline due to habitat loss; fragmentation; forestry; altered fire regimes and range contraction The combination of fragmentation; bushfires; drought; forestry; and range contraction is likely to lead to decline in the yellow bellied glider (south eastern) over the next three generations (see Table 1).
Impacts of the 2019 20 bushfires In 2019 20; following years of drought (DPI 2020); catastrophic bushfire conditions resulted in extensive bushfires covering an unusually large area of eastern Australia.
In all surveyed areas; yellow bellied gliders (south eastern) were not detected at high or extreme fire severity sites; and 68 percent of transects had fewer individuals detected than before the bushfires (Craven Daly 2020).
The south eastern NSW sites have a history of timber harvesting but historically low fire frequency (Kavanagh et al. 2021).
It is highly likely that this observed decline in the yellow bellied glider (south eastern) subpopulation at Waratah Creek is due to the impacts of fire (Kavanagh et al. 2021).
Table 4 Summary of on ground survey results for yellow bellied glider (south eastern) Locality Survey date Number of Impact of mild fire Impact of Source sites Severe fire East Gippsland September 30 sites (19 Reduced number of sightings Absent P.
Less likely to be present at sites in and high fire severely burned forest frequency) South east NSW May 2021 8 sites (2 Recorded at two new sites and one site with (sites with a with pre fire previous records.
Not recorded at different a history of forestry detections) site with previous records. and low fire frequency) South east NSW May 2021 1 large 100 3 individuals recorded after the 2019 (sites with a ha site (10 fires; totalling 86 97 decline across all history of forestry transects; all transects. 77 of site burn at moderate and low fire with pre fire (42 ); high (30 ); or extreme (5 ) frequency) detections) severity. 20 burnt at low severity; 3 unburnt.
However; given that large scale fire and catastrophic drought were not accounted for during projection of future declines ; and such events are predicted to increase in frequency (CSIRO Bureau of Meteorology 2015); it is likely that this decline exceeds percent and is closer to the lower bounds of 38 percent (Legge et al. 2021).
Elevated temperatures; combined with drought stress may lead to similar declines in yellow bellied glider (South eastern).
This should include modelling of the health of significant habitat species; eco physiological controls on sap flow; and future distribution of high fire risk and extreme events (especially drought and bushfires).
Impacts of the 2019 20 bushfires In 2019 20; following years of drought (DPI 2020); catastrophic bushfire conditions resulted in extensive bushfires covering an unusually large area of eastern Australia.
However; given that large scale fire and catastrophic drought were not accounted for during projection of future declines ; and such events are predicted to increase in frequency (CSIRO Bureau of Meteorology 2015); it is likely that this decline exceeds percent and is closer to the lower bounds of 38 percent (Legge et al. 2021).

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